Airborne contaminants in various indoor environments have become a significant concern with regard to the health and comfort of persons occupying such, particularly in places of business, institutional and public buildings and virtually any indoor environment wherein it is desired to eliminate solid particles (dust, pollen, mold, lint, fiber), other particulates, such as tobacco smoke and certain aerosols, and gas phase pollutants, such as formaldehyde, various volatile organic compounds and other odor causing gasses. The composition and concentration of such contaminants will, of course, vary depending on the particular environment and the sources which generate various concentrations of the above-mentioned contaminants.
One particular type of indoor environment which has been subject to heightened public awareness and local and regional governmental regulation is that wherein tobacco smoke is generated. Regulations and increased public awareness of the effects of tobacco smoke have resulted in isolation of certain indoor areas wherein the smoking of cigarettes and other tobacco products is permitted. Restaurants, night clubs and taverns, for example, have been required, through regulation and public sentiment, to segregate persons using tobacco products from non-smokers within their facilities. Accordingly, this action tends to concentrate the generation of tobacco smoke and poses a significant problem in properly removing contaminated air from the area where smoking is permitted so as to provide a clean and comfortable environment for persons occupying the smoking area as well as persons occupying the non-smoking areas of the same facility.
In order to avoid costly construction work and other modifications of existing facilities and to retain the aesthetic appeal of certain facilities, such as restaurants and similar establishments, there has been a strongly felt need to provide a suitable air circulation, filtration and purification system which will remove airborne contaminants from the area where these contaminants are being generated with minimum cost while retaining a pleasant atmosphere for the occupants of the facility. These same problems arise for various other facilities, such as private business and public buildings, wherein the use of tobacco products is permitted only in certain areas or zones. Moreover, there are also other instances wherein the circulation and purification of air with respect to a particular indoor environment is required or desired and wherein contamination of the air is generated by certain work processes, for example.
Conventional indoor air conditioning systems do not properly overcome the contaminated air problems in facilities such as those mentioned above. Conventional ventilating systems, for example, usually remove contaminated air from the environment being treated and replace it with air from another environment, including outdoor contaminated air. However, bringing in outdoor air may require the removal of contaminants as well as cooling or heating the air, thereby significantly increasing energy costs. A related problem with respect to treating air drawn into the indoor environment to be controlled also pertains to the fact that using outdoor air, which may contain various gasses and volatile organic compounds which have been produced in the outdoor environment, such as from the burning of fossil fuels, does not solve the contamination problem within the particular indoor environment which is to be controlled.
Accordingly, there has been a significant and growing need for an effective air filtration and purification system which may be easily installed in existing indoor facilities, as well as newly constructed facilities, particularly for circulating and purifying air within a particular area, zone or room within the indoor facility. It is to these ends that the present invention has been developed.